Systems and methods for group communication using a mobile device with mode transition based on motion

ABSTRACT

Methods and systems of communication using a mobile device that include detecting a movement of the mobile device associated with transitioning from speaker phone mode to earpiece mode, or vice versa, and in response to detecting such movement, automatically transitioning the device to a different mode of operation. The detected action may be the motion and/or positioning of the device handset, such as the movement of the handset towards or away from the user&#39;s ear, and/or the placement of the handset on a surface in a face-up or face-down position. Further methods and systems for transitioning between communication pathways and security modes in response to a detected movement of the mobile device.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.13/479,251 entitled “Systems and Methods for Group Communication Using aMobile Device With Mode Depending On User Proximity or Device Position”;U.S. patent application Ser. No. 13/479,255 entitled “Systems andMethods for Establishing A Group Communication Based on Motion of aMobile Device”; and U.S. patent application Ser. No. 13/479,258 entitled“Systems and Methods for Group Communication Using a Mobile Device UsingMotion and Voice Activated Controls” filed concurrently herewith, all ofwhich are incorporated herein by reference for the subject matterdisclosed in their respective claims.

BACKGROUND

For group communications between mobile devices, there exist a number ofgroup communication applications, such as “Push-to-Talk” (PTT)applications, which utilize half-duplex communication between two ormore mobile devices. These applications may be utilized on various typesof mobile devices, such as smartphones, which may employ a touchscreeninterface. In such devices which may have few or no hardware buttons,users must tap or touch the display instead of pressing a traditionalhardware PTT button to request/relinquish control of the “floor” in ahalf-duplex group communication session. This need to touch the displayscreen can sometimes be problematic in the context of atouchscreen-based device, as it can be difficult to hold and maneuverthe device handset while simultaneously touching/manipulating thedisplay screen. The most natural way to operate a handset during a groupcommunication session is in speakerphone mode, which enables the user tohear incoming voice communications and view media content while alsomaking it easier to navigate and manipulate the touchscreen interface asneeded.

Of course, one drawback to using the mobile device in speakerphone modeis that it provides little privacy for the participants of the groupcommunication. In order to speak in a more private manner, such as whenthe user enters a crowded room or when the group conversation veers tosensitive subject matter, the user must take a particular action toswitch the device from speakerphone mode to earpiece mode beforebringing the handset to his/her ear. Similarly, when the user desires toswitch back to speaker mode, the user must take another action toaccomplish the switch from earpiece mode to speakerphone mode. Also,when one user in the group switches from speakerphone mode to earpiecemode, or vice versa, there is no way for the other users in the group toknow this has occurred.

SUMMARY

The various embodiments include methods, systems and devices forconducting group communications using a first mobile device, includingcommunicating with at least one second mobile device in a public mode,detecting a first motion corresponding to a user of the first mobiledevice moving the first mobile device from a first position to a secondposition, transitioning from a public mode to a private mode in responseto the detected first motion, and sending a message to the at least onesecond mobile device indicating a transition from a public mode to aprivate mode.

Further embodiments include methods, systems and devices for conductinggroup communications using a first mobile device, includingcommunicating with at least one second mobile device in a public mode,receiving a message from the at least one second mobile deviceindicating a transition from public mode to private mode, andsuppressing communication at the first mobile device until an indicationof user compliance with the transition to public mode is detected.Suppressing communication at the first mobile device may involvesuspending forced audio messages from the mobile device.

Further embodiments include methods, systems and devices for conductinggroup communications using a first mobile device, includingcommunicating with at least one second mobile device using a firstsecurity setting, detecting a first motion of the first mobile devicecorresponding to a user moving the first mobile device from a firstposition to a second position, transitioning to a second securitysetting in response to the detected first motion, and communicating withthe at least one second mobile device using the second security setting.

Further embodiments include methods, systems and devices for conductinggroup communications using a first mobile device, includingcommunicating with at least one second mobile device over a firstcommunication pathway, detecting a first motion of the first mobiledevice corresponding to a user moving the first mobile device from afirst position to a second position, establishing a communicationchannel with the at least one second mobile device over a secondcommunication pathway in response to the detected first motion, andcommunicating with the at least one second mobile device over the secondcommunication pathway.

Further embodiments include methods, systems and devices for conductinggroup communications using a first mobile device, includingcommunicating with at least one second mobile device using a firstcommunication infrastructure, detecting a first motion of the firstmobile device corresponding to a user moving the first mobile devicefrom a first position to a second position, transitioning to a secondcommunication infrastructure in response to the detected first motion,and communicating with the at least one second mobile device using thesecond communication infrastructure.

Various embodiments include mobile communication devices and serversincluding processors configured to perform operations of the embodimentmethods disclosed herein. Various embodiments also include mobilecommunication devices and servers including means for performingfunctions of the embodiment methods disclosed herein. Variousembodiments also include non-transitory processor- and server-readablestorage media having stored thereon processor-executable instructionsconfigured to cause a processor to perform operations of the embodimentmethods disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and together with the general description given above and thedetailed description given below, serve to explain the features of theinvention.

FIG. 1 is a system diagram of an example system for group communicationbetween a plurality of mobile devices.

FIG. 2 schematically illustrates positions and movements of a mobiledevice handset that may be detected by the mobile device according tovarious embodiments.

FIG. 3A is a process flow diagram illustrating an embodiment method oftransitioning between a public mode of communication and a private modeof communication in a mobile device.

FIG. 3B is a process flow diagram illustrating an embodiment method oftransitioning between a private mode of communication and a public modeof communication in a mobile device

FIG. 4 is a process flow diagram illustrating an embodiment method ofgroup communication using a mobile device wherein at least one mobiledevice in the communication transitions from operating in public mode tooperating in private mode.

FIG. 5A is a process flow diagram illustrating an embodiment method oftransitioning between a public mode of communication associated with afirst security setting and a private mode of communication associatedwith a second security setting in a mobile device.

FIG. 5B is a process flow diagram illustrating an embodiment method oftransitioning between a private mode and a public mode that includeschanging a security setting of the communication session.

FIG. 6A is a process flow diagram illustrating an embodiment method oftransitioning between a public mode associated with half-duplexcommunication and a private mode associated with full-duplexcommunication using a mobile device.

FIG. 6B is a process flow diagram illustrating an embodiment method oftransitioning between a private mode associated with full-duplexcommunication and a public mode associated with half-duplexcommunication using a mobile device.

FIG. 7 is a process flow diagram illustrating an embodiment method oftransitioning between a public mode associated with communication over afirst communication pathway and a private mode associated withcommunication over a second communication pathway using a mobile device.

FIG. 8 is a process flow diagram illustrating an embodiment method oftransitioning between a public mode associated with communication usinga first communication infrastructure and a private mode associated withcommunication using a second communication infrastructure using a mobiledevice.

FIG. 9 is a process flow diagram illustrating an embodiment method ofmodifying the operating mode of a mobile device in response to adetected movement of the device corresponding to the user placing thedevice on a surface.

FIG. 10 is a process flow diagram illustrating an embodiment method ofmodifying the operating mode of a mobile device in response to adetected motion of the device corresponding to the user placing thedevice face-down on a surface.

FIG. 11A is a process flow diagram illustrating an embodiment method ofvoice activated half-duplex communication using a mobile device.

FIG. 11B is a process flow diagram illustrating an embodiment method ofhalf-duplex communication using a mobile device wherein the devicerelinquishes control of the floor based on the silence of the user.

FIG. 11C is a process flow diagram illustrating an embodiment method ofcontrolling floor access for a plurality of mobile devices by a server.

FIG. 12 is a process flow diagram illustrating an embodiment method forestablishing a new communication channel with at least one second mobiledevice in response to a detected motion of a first mobile device.

FIG. 13 is a process flow diagram illustrating a further embodimentmethod for establishing a new communication channel with at least onesecond mobile device based on a detected motion of a first mobiledevice.

FIG. 14 is a process flow diagram illustrating a further embodimentmethod for establishing a new communication channel with at least onesecond mobile device based on a detected motion of a first mobiledevice.

FIG. 15 is a process flow diagram illustrating a method for groupcommunication with a mobile device in which a communication session maybe paused or suspended based on a detected motion of the mobile device.

FIG. 16A is a process flow diagram illustrating an embodiment method forinitiating a half-duplex communication session based on the detectedmotion of a mobile device.

FIG. 16B is a process flow diagram illustrating an embodiment method forinitiating and controlling a half-duplex communication session based onthe detected motion of a mobile device.

FIG. 17 is a system block diagram of a wireless communication device foruse with various embodiments.

FIG. 18 is a system block diagram of a server suitable for use withvarious embodiments.

DETAILED DESCRIPTION

The various embodiments will be described in detail with reference tothe accompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.References made to particular examples and implementations are forillustrative purposes, and are not intended to limit the scope of theinvention or the claims.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other implementations.

The terms “mobile device,” “mobile computing device,” “mobilecommunication device” and “wireless communication device” are usedinterchangeably herein to refer to any one or all of cellulartelephones, smartphones, personal or mobile multi-media players,personal data assistants (PDA's), laptop computers, tablet computers,smartbooks, palm-top computers, wireless electronic mail receivers,multimedia Internet enabled cellular telephones, wireless gamingcontrollers, and similar personal electronic devices which include aprogrammable processor, memory, and transceiver circuitry for conductinggroup communication with at least one other mobile device.

In overview, various embodiments include methods and systems ofcommunication using a mobile device that includes detecting a movementof the mobile device associated with transitioning from speaker phonemode to earpiece mode, or vice versa, and in response to detecting suchmovement, automatically transitioning the device to a different mode ofoperation. In particular, the detected action may be the motion and/orpositioning of the device handset, such as the movement of the handsettowards or away from the user's ear, and/or the placement of the handseton a surface in a face-up or face-down position. How the device detectsthe motion and/or positioning of the handset is not considered criticalto the various embodiments of the invention. In general, any suitablesystem or technique for detecting motion, position and/or orientation ofa handset, such as accelerometers, gyroscopes, or other sensors, whichcan be correlated to a particular action of a user may be utilized.

In various embodiments, the movement that is monitored and detected maybe a motion of the device corresponding to the user bringing the deviceto his/her ear. In response to detecting this motion, the device maytransition from a public mode of operation (e.g., half-duplex inspeakerphone mode) to a private mode of operation (e.g., full duplexearpiece mode or traditional cellphone mode). Similarly, anothermovement that may be monitored and detected may be a motion of thedevice corresponding to the user pulling the device away from his/herear. In response to detecting this motion, the device may transitionfrom a private mode of operation (e.g., full duplex earpiece mode ortraditional cellphone mode) to a public mode of operation (e.g.,half-duplex in speaker mode).

In these embodiments, the transition between public mode and privatemode may entail switching between half-duplex and full-duplexcommunication. The transition between public mode and private mode mayalso include a transition from sending/receiving unencrypted data toencrypting the communication session, and vice versa. The transitionbetween public mode and private mode may also include changing thecommunication pathway of the call, such as routing the call through adifferent network or server, using a different security mode, ortransitioning from a server-mediated communication to a directpeer-to-peer communication between two or more mobile devices.

In further embodiments, the transition between private mode and publicmode may also include sending a signal to other device(s) in a groupcommunication session to inform the devices that the user has switchedfrom public mode to private mode or vice versa. The transition betweenpublic and private mode in one device may force a similar transition inother device(s) in the group. In some embodiments, the transitionbetween public and private mode on one device may suspend or otherwisesuppress communications until one or more other device(s) in the groupsignal their compliance with the new mode. Suppressing communicationsmay involve suspending forced audio messages from one or more of themobile devices in the group.

In further embodiments, the device may transition to a differentcommunication infrastructure in response to detecting a motion of thedevice corresponding to the user either bringing the device to his/herear or pulling the device away from his/her ear. For example, moving thephone away from the ear may cause the phone to unlock video or othermedia features, such as by transitioning from 3G to 4G. As anotherexample, moving the phone to the ear may cause the phone to transitionto higher-quality voice communication. Transitioning to higher-qualityvoice communications may include one or more of switching to a higherQuality of Service (QOS), utilizing a wider band codec or changing to adifferent codec, and activating noise cancellation feature. In someembodiments, moving the device to the ear may cause the device tore-allocate resources (e.g., bandwidth) previously used for streamingvideo or other media content in order to provide higher-quality voicecommunication.

In further embodiments, the action that is detected may be the userplacing the mobile device down on a stable (and optionally non-moving)surface. In response to this action, the device may remain in an activemode broadcasting received audio from the speaker. While the device isin this active mode, the device may monitor for the presence orproximity of the user, such as by detecting the user's voice, detectinga movement of the device, detecting the use of other device(s) by theuser in the vicinity, or using biometric sensors. When the device doesnot detect the presence of the user for a predetermined time period, thedevice may enter a non-active communication mode since the user may havestepped away from the device, and thus cannot monitor the communication.In the non-active communication mode, the device may stop broadcastingreceived audio and enter a mute mode so that others cannot eavesdrop orbutt into the conversation. In a further aspect of this embodiment, thedevice may optionally record or buffer incoming communications for laterplayback when the user returns. In this embodiment, the user's devicemay also optionally notify the other device(s) on the call that the usermay not be listening or may have stepped away from the device, eventhough the user's device remains connected to the group communicationsession. The device may return to an active mode in response to anaction of the user (e.g., the user picks up or moves the phone, or thedevice otherwise detects the user's presence). In a further aspect ofthis embodiment, the device may terminate the communication after aspecified “timeout” period in the non-active communication mode.

In further embodiments, the action that is detected may be the userplacing the mobile device face down on a surface, which the device maytreat as a command to (1) hang-up or otherwise terminate thecommunication session, or (2) enter a non-active communication mode asdescribed above. In the case of (2) entering a non-active communicationmode, the phone may be configured to hang-up or otherwise terminate thecommunication session after a specified “timeout” period.

In further embodiments, the device may detect a voice command of a userand send a request to a server for control of the “floor” in a groupcommunication session. Broadly speaking, the fifth embodiment includes“voice-activated” Push-to-Talk (PTT) communication. In variousembodiments, the device may send the request for the floor in a PTTcommunication session upon detecting the user speaking, upon detectingthe user speaking at a pre-determined volume, or upon detectingkeyword(s) spoken by the user (i.e., using voice recognition software).The detection of silence may trigger release of the floor, which may beafter a specified time-out period. In one embodiment, the device mayrelay voice commands from the user to the server, such as the usercommanding the server to grant the user's device floor access. Inresponse to the voice command, the server may queue up or schedule theuser's device for floor control when it becomes available.

Further embodiments include methods and systems of communication using amobile device that includes detecting a movement of the mobile devicecorresponding to a particular user action, and in response to detectingsuch movement, automatically establishing a new communication channelwith one or more target device(s). In other words, a particular movementof the device (e.g., a rotation, flicking, shaking of the device)triggers a phone call being placed, or the “floor” being requested in ahalf-duplex communication session, or a video call being started, etc.In embodiments, the new communication channel may be a synchronouscommunication channel, such as a full-duplex or half-duplex voice orvideo channel (as opposed to an asynchronous channel, such as e-mail orSMS).

Further embodiments include methods and systems for initiating and/orcontrolling a half-duplex communication application based on thedetected motion of the device handset. For example, during a PTTcommunication session a first mobile device may detect a first motionand in response to the detected motion, the device may initiate orlaunch a half-duplex group communication application, such as aPush-to-Talk (PTT) application. A detected second motion may trigger thedevice to request the “floor” in a half-duplex communication. A detectedthird motion may trigger the device to release the floor.

The various embodiments may be implemented within a variety of wirelesscommunication systems 100, an example of which is illustrated in FIG. 1.The communication system 100 may include a plurality of mobile devices102, 104, 106, 108, which may be configured to communicate via cellulartelephone network, a radio access network, WiFi network, WiMAX network,and/or other well known technologies. Mobile devices 102, 104, 106, 108may be configured to receive and transmit voice, data and controlsignals to and from a base station 110 (e.g., base transceiver station)which may be coupled to a controller (e.g., cellular base station, radionetwork controller, service gateway, etc.) operable to communicate thevoice, data, and control signals between mobile devices and to othernetwork destinations. The base station 110 may communicate with anaccess gateway 112, which may be a packet data serving node (PDSN), forexample, and which may serve as the primary point of entry and exit ofwireless device traffic. The access gateway 112 may be implemented in asingle computing device or in many computing devices, either within asingle network or across a wide area network, such as the Internet.

The access gateway 112 may forward the voice, data, and control signalsto other network components as user data packets, provide connectivityto external packet data networks, manage and store contexts (e.g.network internal routing information, etc.) and act as an anchor betweendifferent technologies (e.g., 3G and 4G systems). The access gateway 112may also coordinate the transmission and reception of data to and fromthe Internet 114, and the transmission and reception of voice, data andcontrol information to and from an external service network connected tothe Internet 114 and other base stations 110 and wireless receivers 102,104, 106, 108.

The access gateway 108 may connect the receiver devices 102 to a servicenetwork 116. The service network 116 may control a number of servicesfor individual subscribers, such as management of billing data andselective transmission of data, such as multimedia data, to a specificreceiver device 102, 104, 106, 108. The service network 116 may beimplemented in a single computing device or in many computing devices,either within a single network or across a wide area network, such asthe Internet 114. The service network 116 may typically include one ormore servers 120, such as a group communication server described infurther detail below.

The mobile device may be, for example, a smartphone 102, 104, a tabletcomputer 106, a cellular telephone 108, or any other suitable mobiledevice. In general, the mobile devices may include a platform that canreceive and execute software applications, data and/or commandstransmitted over the wireless network that may ultimately come from theservice network 116, the Internet 114 and/or other remote servers andnetworks. The mobile device may include a transceiver operably coupledto a processor, which may be an application specific integrated circuit(ASIC), microprocessor, logic circuit, or other data processing device.The processor may execute an application programming interface (“API”)layer that interfaces with any resident programs in an internal memoryof the mobile device. The internal memory may be comprised of read-onlyor random-access memory (RAM and ROM), EEPROM, flash cards, or anymemory common to computer platforms. The mobile device may also includea local database that stores applications not actively used in memory.The local database is typically a flash memory cell, but may be anysecondary storage device as known in the art, such as magnetic media,EEPROM, optical media, tape, soft, or hard disk, or the like. Theprocessor may also be operably coupled to external devices such as anantenna, microphone, speaker, display, keypad or other user inputdevice, such as a touchscreen device, as is known in the art.

In embodiments, the components of the mobile device may be provided in acompact housing (i.e., a “handset”) that enables the device to be heldand easily manipulated by a user. The mobile device may also include atleast one sensor that generates signals that may be interpreted by theprocessor to determine the motion, position and/or orientation of thedevice handset at any given time as is known in the art.

In conventional wireless communication systems, a group communicationsession between two or more mobile devices may be arbitrated by a groupcommunication server or a network of such servers (e.g., collectivelyillustrated by server 120 in FIG. 1). The subscribers to a particulargroup communication service (e.g., a push-to-talk (PTT) service, apush-to-transfer (PTX) service, etc.) are thereby permitted tocommunicate with other subscribers of the same service with messagesbeing exchanged in a PTT communication session either through, or at thecontrol of, the group communication server 120. In the case of a groupaudio session, this means audio packets may be transmitted to the groupcommunication server 120 via the wireless network from one of thesubscriber devices (e.g., mobile devices 102, 104, 106, 108), and theserver 120 may forward the audio packets to one or more other subscriberdevices actively participating in the group communication session.Likewise, for group sessions involving other types of media (e.g., textmessages, multimedia messages including video and/or audio, etc.), othertypes of data packets may be exchanged between mobile devices of groupmembers, or subscribers, during the session.

In various embodiments, the group communication server 120 may performarbitration functions between competing demands of the various mobiledevices 102, 104, 106, 109 for use of communication channels over thewireless network. For example, in response to a request from wirelesscommunication device 102 to communicate with one or more other targetdevices in a communication group, including all other devices in thegroup, the server 120 may establish a communication channel between therequesting device 102 and all or a portion of the requested targetdevices in the group. The server 120 may thus grant control of the“floor” to the requesting mobile device 102. In a half-duplexcommunication session, generally only one mobile device may have controlof the “floor” at a given time. The mobile device with control of thefloor may send voice and/or other data, and the other devices may onlyreceive data. Where there exist competing requests amongst devices ofthe group for control of the “floor,” the server 120 may arbitratebetween competing requests based on pre-determined priority criteria.The priority criteria may be established at the time of thecommunication group formation, such as by a group administrator, andstored by the communication server 120. In embodiments, the prioritycriteria may be default priority criteria stored by server 120. In someembodiments, the priority criteria may be established on an ad hoc basisby one or more of the mobile devices (e.g., 102, 104, 106, 108) in thegroup. The server 120 may also maintain records for each communicationgroup, including the subscriber devices constituting each group, and mayalso track the status of each mobile device in the group (e.g., whetherthe device is available, unavailable, unreachable, etc.).

Embodiments include methods and systems of communication using a mobiledevice that includes detecting a movement of the mobile deviceassociated with a particular action by a user of the device, and inresponse to detecting such movement, transitioning the mobile device toa different mode of operation. In particular, the user action may be amovement of the device handset, such as the movement of the handsettowards or away from the user's ear, and/or the placement of the handseton a surface in a face-up or face-down position. FIG. 2 schematicallyillustrates various movements that may be detected by the mobile deviceaccording to various embodiments. FIG. 2 shows a mobile device handset201 that includes a front surface 203, a rear surface 205 and at leastone sensor 210 for detecting the movement of the device. The sensor 210may be an accelerometer, gyroscope, or other sensors, includingcombinations of sensors, that may be used to detect a motion and/orchange in position/orientation of a handset 201 that may be correlatedto a particular action by a user of the device.

FIG. 2 illustrates the handset 201 in a first position 202, whichcorresponds to the device operating in a public mode. In embodiments,the public mode may be the default operating state for the mobile devicein a group communication session. In some embodiments, the sensor(s) 210may indicate that the device handset 201 is in a position and/ororientation corresponding to operation in a public mode. For example,the sensor(s) 210, by detecting the position, orientation and/ormovements of the handset 201, may indicate that the handset 201 is beingheld in front of the user 212 and away from the user's ear (as shown inFIG. 2), or is within a holster or other holding device, or is in amoving vehicle, or is in any other position/orientation that may becorrelated to a public mode of operation. The device operating in apublic mode in the first position 202 may operate using speakerphonemode (e.g., providing forced audio over the device loudspeaker), and maycommunicate over a half-duplex communication channel with one othermobile device in a communication group.

FIG. 2 illustrates the device in a second position 204, in which thehandset 201 is positioned proximate the ear of the user 212. Thisposition 204 may correspond to the device operating in a private mode.The sensor(s) 210 may detect a motion of the handset 201 (indicated bydashed line 222) corresponding to a transition between the firstposition 202 and the second position 204. The sensor(s) 210 my alsodetect a motion of the handset 201 (indicated by dashed line 224)corresponding to a transition between the second position 204 and thefirst position 202.

FIG. 2 also illustrates the device in a third position 206, in which thehandset 201 is placed on a stable, optionally stationary surface 214,such as a table or desk. In the third position 206, the handset 201 isplaced in a “face-up” position with the front surface 203 of the handset201 faced up towards the user 212. In embodiments, the sensor(s) 210 maybe configured to detect when the device handset 201 is in the thirdposition 206. The sensor(s) 210 may also be configured to detect amotion of the handset 201 (indicated by dashed line 226) correspondingto a transition between the first position 202 (or optionally the secondposition 204) and the third position 206. The sensor(s) 210 may alsodetect a motion of the handset 201 (indicated by dashed line 230)corresponding to a transition between the third position 206 and thefirst position 202 (or optionally the second position 204).

FIG. 2 also illustrates the device in a fourth position 208, in whichthe handset 201 is placed “face-down” on a stable, optionally stationarysurface 214, such as a table or desk. In the fourth position 208, thehandset 201 is placed in a “face-down” position with the rear surface205 of the handset 201 faced up towards the user 212. In embodiments,the sensor(s) 210 may be configured to detect when the device handset201 is in the fourth position 208. The sensor(s) 210 may also beconfigured to detect a motion of the handset 201 (indicated by dashedline 228) corresponding to a transition between the first position 202(or optionally the second position 204) and the fourth position 208. Thesensor(s) 210 may also detect a motion of the handset 201 (indicated bydashed line 234) corresponding to a transition between the fourthposition 208 and the first position 202 (or optionally the secondposition 204). The sensor(s) 210 may also detect a motion of the handset201 (indicated by dashed line 232) corresponding to a transition betweenthe third position 206 and the fourth position 208 (i.e., turning thehandset 201 over from a face-up to a face-down position). The sensor(s)210 may also detect a motion of the handset 201 (indicated by dashedline 236) corresponding to a transition between the fourth position 208and the third position 206.

FIG. 3A is a process flow diagram illustrating an embodiment method 300of transitioning between a public mode of communication and a privatemode of communication in a mobile device. In embodiment method 300, afirst mobile device, such as mobile device 102 in FIG. 1, may establisha communication session with one or more second mobile device, such asdevice(s) 104, 106 and/or 108 in FIG. 1, in a public mode in block 302.The first mobile device 102 may detect a motion of the devicecorresponding to the user bringing the handset to his/her ear in block304. The detected motion may be the motion corresponding to a transitionbetween the first position 202 and the second position 204, indicated bydashed line 222 in FIG. 2. In response to this detected motion, thedevice may transition from a public mode to a private mode in block 306.In one example, the transition from a public mode to a private mode maychange the audio path of the mobile device, such as causing the deviceto switch from a speakerphone mode to an earpiece mode. The first mobiledevice 102 may send a message to the other device(s) in the groupcommunication session to inform the device(s) that the user has switchedfrom public mode to private mode in block 308. In optional block 310,the first mobile device 102 may receive a message from the otherdevice(s) in the group communication session indicating that the otherdevice(s) have also transitioned to private mode.

FIG. 3B is a process flow diagram illustrating an embodiment method 301of transitioning between a private mode of communication and a publicmode of communication in a mobile device. In embodiment method 301, afirst mobile device, such as mobile device 102 in FIG. 1, may establisha communication session with one or more second mobile device(s), suchas device(s) 104, 106 and/or 108 in FIG. 1, in a private mode in block312. The mobile device 102 may be in the second position 204 shown inFIG. 2 with the device handset 201 being held proximate the ear of theuser 212, and the device may be operating in earpiece mode while inprivate mode. The first mobile device 102 may detect a motion of thedevice corresponding to the user moving the handset away from his/herear in block 314. The detected motion may be the motion corresponding toa transition between the second position 204 and the first position 202,indicated by dashed line 224 in FIG. 2. In response to this detectedmotion, the device may transition from a private mode to a public modein block 316. In one example, the transition from a private mode to apublic mode may change the audio path of the device, such as causing thedevice to switch from earpiece mode to speakerphone mode. The firstmobile device 102 may send a message to the other device(s) in the groupcommunication session to inform the device(s) that the user has switchedfrom private mode to public mode in block 318. In optional block 320,the first mobile device 102 may receive a message from the otherdevice(s) in the group communication session indicating that the otherdevice(s) have also transitioned to public mode.

In general, it may typically be assumed that when the user of the firstdevice switches from private mode to public mode (e.g., moves thehandset away from his/her ear and switches to speakerphone mode), theuser is in a private setting or is otherwise not concerned about thecommunication session being overheard by third-parties. In some cases,however, the user may not be paying attention to his/her surroundings,and may not realize that he/she has inadvertently transitioned to apublic mode during a conversation that is intended to be private. Insome embodiments, the first mobile device 102 may provide feedback tothe user of the first mobile device (e.g., an audio, visual and/orhaptic signal) indicating that the device has transitioned to a publicmode, and in some embodiments, the mobile device 102 may suppress and/orbuffer incoming audio (e.g., by suspending forced audio messages) untilthe user indicates his/her assent to the mode switch, as is discussed infurther detail below in connection with FIG. 4.

Of course, the user(s) of the other device(s) in the communicationsession may object to the first user transitioning to public mode inwhat was initially a private conversation. By sending a message to theother device(s) indicating that the first device has transitioned topublic mode, the other user(s) may be made aware that the conversationmay be less private than previously assumed, and these users may adjusttheir conduct accordingly.

FIG. 4 is a process flow diagram illustrating an embodiment method 400of group communication by a plurality of mobile devices in a public modewherein at least at least one device transitions from operating inpublic mode to operating in private mode. Embodiment method 400 may beapplicable, for example, in connection with embodiment method 300 shownin FIG. 3A, in which the first mobile device transitions from publicmode to private mode and sends a message to the at least one secondmobile device indicating a transition from public mode to private mode.In this example, embodiment method 401 may be performed by the at leastone second mobile device in response to receiving the message from thefirst device indicating the transition to private mode. Similarly, asshown in FIG. 4, the method 400 may be performed by the first mobiledevice in response to another mobile device in the group communicationsession transitioning from a public mode to a private mode.

As shown in FIG. 4, a first mobile device, such as mobile device 102 inFIG. 1, may establish a communication session or be communicating withone or more second mobile device(s), such as device(s) 104, 106 and/or108 in FIG. 1, in a public mode in block 402. The first mobile device102 may receive a message from at least one second mobile deviceindicating that the at least one second mobile device has transitionedfrom a public mode to a private mode in block 404. As discussed above,this message may be sent by the at least one second mobile devicepursuant to block 308 of embodiment method 300 shown in FIG. 3A, andthis message may be sent in response to a detected motion of the mobiledevice, such as the motion from a first position 202 to a secondposition 204 indicated by dashed line 222 in FIG. 2. In block 406 ofembodiment method 400, the first mobile device 102 may provide anindication to the user of the device 102 that the at least one secondmobile device has transitioned from a public mode to a private mode. Inembodiments, the indication may be a feedback cue (e.g., an audio,visual and/or haptic signal), perceptible to the user of the firstmobile device 102, indicating that the at least one other device in thegroup communication session has transitioned from a public mode to aprivate mode. The feedback cue may be the cessation of the audio feedfrom the at least one second mobile device. The user of the first device102 may thus be notified that at least one other user in the groupcommunication session desires to speak in a more private manner. Thefirst mobile device 102 may also suppress (e.g., suspending, blocking orotherwise preventing audible playing) the audio feed from the devicethat has transitioned to private mode in block 408. In an embodiment,suppressing communication at the first mobile device may involvesuspending forced audio messages from the mobile device. In this way,the audio signals from a user who has transitioned his/her device toprivate mode (and presumably intending to converse more privately) isnot played on a mobile device operating in public mode, which may havethe speakerphone enabled and could easily be overheard by third-parties

While the first mobile device 102 suppresses the audio from the at leastone second mobile device operating in private mode, at optional block410 the first mobile device 102 may buffer or otherwise record theincoming audio feed from the at least one second mobile device for laterplayback. Suppressing and buffering communication at the first mobiledevice may involve suspending forced audio messages from the secondmobile device. In this way, the user of the first mobile device 102 maychose to hear the “suppressed” portion of the group communicationsession when the device is in private mode or when the user is in a moreprivate setting.

In embodiments, the first mobile device 102 may continue to buffer orrecord the audio until the communication session is terminated, or maybuffer or record for a pre-determined time period, after which the firstmobile device 102 may automatically terminate the call.

In embodiments, the first mobile device 102 may detect the user'scompliance with the mode transition from public mode to private mode bythe at least one second mobile device in block 411. In some embodiments,the device 102 may detect compliance with the mode transition bydetecting motion of the device corresponding to the user bringing thehandset to his/her ear. The detected motion may be the motioncorresponding to a transition between the first position 202 and thesecond position 204, indicated by dashed line 222 in FIG. 2. As analternative to, or in addition to, detecting motion of the device, thefirst mobile device 102 may detect an input from the user that may bereceived at a user interface (e.g., a touchscreen display, keypad, etc.)of the device 102 indicating that the user complies with the modetransition. For example, when the device 102 provides the indication tothe user of the transition from public mode to private mode by anotherdevice in the group communication, the device 102 may provide menuoption(s) to the user, such as the option to continue the call in a moreprivate manner (e.g., turn off speakerphone mode and continue the callin earpiece mode), to continue the call in speakerphone mode (e.g.,where the user is unconcerned about third-party eavesdropping of theconversation), and/or to terminate the call.

While the user has not indicated compliance with the mode transition(i.e., determination block 412=“No”), the first mobile device 102 maycontinue to suppress audio from the at least one second mobile device atblock 408, and may optionally buffer/record the audio from the at leastone second mobile device at block 410, until either the groupcommunication is terminated, or in some embodiments, for apre-determined timeout period, after which the first mobile device 102may automatically end the call. When the first mobile device 102 detectsthat the user is compliant with the transition from public mode toprivate mode (i.e., determination block 412=“Yes”), then the firstmobile device 102 may resume the audio feed from the at least one secondmobile device in block 416. Optionally, the first mobile device 102 mayplay back the buffered/recorded audio from the at least one secondmobile device in optional block 414. The first device 102 mayautomatically play back the buffered/recorded audio once compliance withthe mode transition is detected (i.e., allowing the user to hear themissed portion of the conversation), and may continue to buffer/recordthe conversation until the recorded portion of the conversation “catchesup” to the live audio feed. In other embodiments, the device 102 maycontinue with the “live” audio feed, and store the buffered/recordedportion of the communication session in memory for later playback.

Embodiment methods include transitioning between a public mode and aprivate mode in a group communication session based on a detectedmovement of a mobile device handset. As discussed above, the transitionbetween public mode and private mode may include a change in the audiopath of the mobile device. Specifically, a transition between publicmode and private mode may trigger a change from speakerphone mode toearpiece mode. Conversely, the transition from private mode to publicmode may trigger a change from earpiece mode to speakerphone mode. Inaddition to changing the audio path of the mobile device, the transitionfrom public mode to private mode may also include additional changes,such as a change in the security settings of the communication session.For example, when the mobile device is operating in public mode (e.g.,operating in speakerphone mode where the conversation may be overheardby third-parties), the security of the conversation may not be aparamount concern. In a public mode, a less robust security posture maybe maintained than when the device is operating in private mode, wherein general the security of the conversation is of greater concern. Insome embodiments, the transition between public mode and private modemay include a change in the encryption scheme used in encrypting datatransmitted between the mobile devices in a group communication session,and may include embodiments in which no encryption is used when themobile device is in public mode, and an encryption feature is activatedwhen the device is in private mode.

FIG. 5A is a process flow diagram illustrating an embodiment method 500of transitioning between a public mode of communication associated witha first security setting and a private mode of communication associatedwith a second security setting in a mobile device. In this exemplaryembodiment, the security setting includes the type of encryption used(e.g., the particular encryption algorithm(s) employed) whentransmitting voice and/or other data over the wireless network to atleast one other mobile device. It will be understood that the change insecurity setting may alternatively or in addition include transmittingthe data over a different (e.g., more or less secure) portion of thewireless network, through a different server or server(s) having varyingdegrees of security, or over a different network entirely. For example,the change in security setting may be associated with a transitionbetween communicating over an open system and a secure system. Thechange may also affect how the mobile devices handle cryptographic keyexchange, for example.

In block 502 of embodiment method 500, a first mobile device, such asmobile device 102 in FIG. 1, may transmit unencrypted messages to atleast one second mobile device, such as device(s) 104, 106 and/or 108 inFIG. 1. The first mobile device 102 may operate in a public mode and maybe in a first position 202 such as shown in FIG. 2. The first mobiledevice 102 may detect a motion of the device corresponding to the userbringing the handset to his/her ear in block 504. The detected motionmay be the motion corresponding to a transition between the firstposition 202 and the second position 204, indicated by dashed line 222in FIG. 2. In response to this detected motion, the device may initiatean encryption feature on the first mobile device in block 506. Theinitiation of the encryption feature may be associated with a transitionfrom a public mode to a private mode, which may further include a changein an audio path from a speakerphone mode to an earpiece mode. With theencryption feature initiated, the first mobile device 102 may transmitencrypted messages to the at least one second mobile device in block508.

In embodiments, a change in security settings on one mobile device, suchas the initiation of an encryption feature in embodiment method 500, mayforce a similar change in other devices that are participating in thegroup communication session. Thus, changing a security setting in onedevice (such as the initiation of an encryption feature in block 506 ofmethod 500) may also include sending a message to the other device(s) inthe communication session and/or to a central server in order toimplement the security setting change across all devices participatingin the communication session.

FIG. 5B is a process flow diagram illustrating an embodiment method 501of transitioning between a private mode and a public mode that includeschanging a security setting of the communication session. The embodimentmethod 501 of FIG. 5B may be the reverse of the embodiment method 500 ofFIG. 5A. In block 510 of method 501, the first mobile device 201 maytransmit encrypted messages to at least one second mobile device. Thefirst mobile device 102 may operate in a private mode and may be in asecond position 204 such as shown in FIG. 2. The first mobile device 102may detect a motion of the device corresponding to the user moving thedevice handset away from his/her ear in block 512. The detected motionmay be the motion corresponding to a transition between the secondposition 204 and the first position 202, indicated by dashed line 224 inFIG. 2. In response to this detected motion, the device may terminate anencryption feature on the first mobile device in block 514. Thetermination of the encryption feature may be associated with atransition from a private mode to a public mode, which may furtherinclude a change in an audio path from an earpiece mode to aspeakerphone mode. With the encryption feature terminated, the firstmobile device 102 may transmit unencrypted messages to the at least onesecond mobile device in block 516.

As with the embodiment method 500, the change in security setting (e.g.,from unencrypted to encrypted transmission) in embodiment method 501 mayforce a similar change in other devices in the communication session.

FIG. 6A is a process flow diagram illustrating an embodiment method 600of transitioning between a public mode associated with half-duplexcommunication and a private mode associated with full-duplexcommunication using a mobile device. As discussed above, embodimentmethods include transitioning between a public mode and a private modein a group communication session based on a detected movement of amobile device handset, where the transition between public mode andprivate mode may include a change in the audio path and/or the securitysettings of the mobile device. Embodiments may also includetransitioning between different types of communication, and inparticular between half-duplex and full-duplex communication based onthe movement of the device handset. As previously noted, during a groupcommunication session, such as a Push-to-Talk session, it is common tooperate the mobile device in a “public” mode, with the speakerphoneactivated to allow the user to hear the often sporadic incoming voicecommunications and view media content while also making it easier tonavigate and manipulate the device interface as needed. When the userdesires a more private conversation using the earpiece mode, it may bemore natural to communicate over a full-duplex communication link, suchas in a conventional phone call. This further has the advantage ofavoiding the need to repeatedly request the “floor” every time the userwants to talk, which may be particularly difficult when the device isheld to the user's ear and the floor must be requested by touchingand/or holding a “virtual” PTT button on a touchscreen interface.

In block 602 of embodiment method 600, a first mobile device 102, suchas mobile device 102 in FIG. 1, may establish a half-duplexcommunication channel with at least one other (i.e., second) mobiledevice, such as device(s) 104, 106, and/or 108 in FIG. 1. The firstmobile device 102 may establish the half-duplex communication channel incoordination with a central server, such as group communication server120 shown in FIG. 1. The first mobile device 102 may communicate withthe at least one second mobile device over the half-duplex communicationchannel in block 604. The device 102 may communicate in a public mode(e.g., with speakerphone activated) and may be in a first position 202such as shown in FIG. 2. The first mobile device 102 may detect a motionof the device corresponding to the user bringing the handset to his/herear in block 606. The detected motion may be the motion corresponding toa transition between the first position 202 and the second position 204,indicated by dashed line 222 in FIG. 2. In response to this detectedmotion, the device establish a full-duplex communication channel withthe at least one second mobile device in block 608. The first mobiledevice 102 may establish the full-duplex communication channel throughthe group communication server 120, or through one or more differentservers, a different network, or a different portion of the samenetwork. In some embodiments, the first mobile device 102 may establisha direct connection to the at least one second mobile device over a widearea network, such as the Internet 114. The first mobile device 102 maycommunicate with the at least one second mobile device over thefull-duplex communication channel at block 610.

In embodiments, a change from half-duplex to full-duplex communicationin the first mobile device may force a similar change in other devicesthat are participating in the group communication session. Thus,establishing a full-duplex communication channel in block 608 ofembodiment method 600 may also include sending a message to the otherdevice(s) in the communication session and/or to one or more servers inorder to implement the change to full-duplex communication across alldevices participating in the communication session.

FIG. 6B is a process flow diagram illustrating an embodiment method 601of transitioning between a private mode associated with full-duplexcommunication and a public mode associated with half-duplexcommunication using a mobile device. The embodiment method 601 of FIG.6B may be the reverse of the embodiment method 600 of FIG. 6A. In block612 of method 601, the first mobile device 201 may establish afull-duplex communication channel with at least one other (i.e., second)mobile device. The first mobile device 201 may communicate with the atleast one second mobile device over the full-duplex communicationchannel in block 614. The first mobile device 102 may operate in aprivate mode and may be in a second position 204 such as shown in FIG.2. The first mobile device 102 may detect a motion of the devicecorresponding to the user moving the device handset away from his/herear in block 616. The detected motion may be the motion corresponding toa transition between the second position 204 and the first position 202,indicated by dashed line 224 in FIG. 2. In response to this detectedmotion, the device may establish a half-duplex communication channelwith the at least one second mobile device in block 618. The firstmobile device 102 may communicate with the at least one second mobiledevice over the half-duplex communication channel in block 620.

As with the embodiment method 600, the change from full-duplex tohalf-duplex communication in embodiment method 601 may force a similarchange in other devices in the communication session. The first mobiledevice 102 may establish the half-duplex communication channel incoordination with a server, such as group communication server 120 inFIG. 1.

FIG. 7 is a process flow diagram illustrating an embodiment method 700of transitioning between a public mode associated with communicationover a first communication pathway and a private mode associated withcommunication over a second communication pathway using a mobile device.As discussed above, embodiment methods include transitioning between apublic mode and a private mode in a group communication session based ona detected movement of a mobile device handset, where the transitionbetween public mode and private mode may include a change in the audiopath, the security settings of the mobile device and/or a transitionbetween half-duplex and full-duplex communication. Embodiments may alsoinclude transitioning between different communication pathways based onthe movement of the device handset. The transition to a differentcommunication pathway may include, for example, communicating over adifferent network or portion of a network, including communicatingthrough or under the control of a different server or group of servers.The transition to a different communication pathway may be associatedwith a change in security posture of the communication (e.g., sendingdata packets through an open system versus a secure system) and/or achange in the type of communication (e.g., a transition betweenhalf-duplex and full-duplex communication). In one embodiment, thetransition to a different communication pathway may comprise atransition between sending voice and/or other data through a centralpoint (e.g., a server) to a peer-to-peer or point-to-point type model,in which the communicating devices may send the data directly to eachother over a wide area network, such as the Internet 114 shown in FIG.1, without the intervention of a central logical entity, such as groupcommunication server 120 in FIG. 1. In embodiments, the change from aserver-mediated communication pathway to a peer-to-peer communicationpathway may be associated with a transition from a public mode ofcommunication to a private mode of communication. This may provideadditional privacy by eliminating the central server from the loop. Thechange to a different communication pathway may also allow the networkto more efficiently allocate resources. For example, the groupcommunication server 120 may set up a group communication sessionbetween devices in a public mode, and when the devices wish for privatecommunication, the server 120 may hand-off the session to the mobiledevices, which may establish a direct peer-to-peer connection with theother device(s) in the group based on the known IP addresses of theother device(s). In embodiments, the transition to a differentcommunication pathway may be performed by the mobile device without theknowledge or intervention of the user of the device.

In block 702 of embodiment method 700, a first mobile device 102, suchas mobile device 102 in FIG. 1, may establish a communication channelwith at least one second mobile device, such as device(s) 104, 106,and/or 108 in FIG. 1, over a first communication pathway. The firstmobile device 102 may establish the first communication pathway througha central server, such as group communication server 120 shown inFIG. 1. The first mobile device 102 may communicate with the at leastone second mobile device over the first communication pathway in block704. The device 102 may communicate in a public mode (e.g., withspeakerphone activated) and may be in a first position 202 such as shownin FIG. 2. The first mobile device 102 may detect a motion of the devicecorresponding to the user bringing the handset to his/her ear in block706. The detected motion may be the motion corresponding to a transitionbetween the first position 202 and the second position 204, indicated bydashed line 222 in FIG. 2. In response to this detected motion, thedevice establish a communication channel with the at least one secondmobile device over a second communication pathway in block 708. Thesecond communication pathway may be through a different network orserver, or through a different portion of the network. In embodiments,the second communication pathway may be a peer-to-peer pathway, asdescribed above. The first mobile device 102 may communicate with the atleast one second mobile device over the second communication pathway atblock 710.

The first mobile device 102 may detect a motion of the devicecorresponding to the user moving the device handset away from his/herear in block 712. The detected motion may be the motion corresponding toa transition between the second position 204 and the first position 202,indicated by dashed line 224 in FIG. 2. In response to this detectedmotion, the device may re-establish the first communication pathway andcontinue the communication session with the at least one second mobiledevice in block 714. In embodiments, the transition from the secondcommunication pathway back to the first communication pathway mayinclude a transition from a peer-to-peer communication pathway to aserver-mediated pathway, and may include sending a request to a centralserver, such as group communication server 120, to establish a groupcommunication session between the mobile devices.

In embodiments, a change from the first communication pathway to thesecond communication pathway, and vice versa, in the first mobile devicemay force a similar change in other devices that are participating inthe group communication session.

FIG. 8 is a process flow diagram illustrating an embodiment method 800of transitioning between a public mode associated with communicationusing a first communication infrastructure and a private mode associatedwith communication using a second communication infrastructure using amobile device. The transition to a different communicationinfrastructure may include, for example, transition to different typesof communication capabilities, modem capabilities, video and other mediacapabilities, etc., based on the detected movement of the devicehandset.

The transition to a different communication infrastructure may include atransition to a different Quality of Service (QoS) for the call, or useof different codecs for higher or lower quality audio transition. Inembodiments, the transition may enable or disable media features, suchas video features, and could, for example, include a transition betweena 3G and a 4G network infrastructure. Generally speaking, according tosome embodiments, the detected movement of the user brining the handsettowards his/her ear may trigger enhanced audio features, such aschanging to a higher QoS and/or a wider band codec (i.e., using adifferent codec), use of noise cancellation features, etc. Conversely,the detected movement of the user moving the device handset away fromhis/her ear may enable enhanced video and/or multimedia features. Inembodiments, the mobile device may reallocate resources, such asbandwidth, based on the detected movement of the device handset. Forexample, when the device handset is held away from the user's ear, thedevice may allocate certain resources to multimedia functions, such assending and receiving media files, viewing videos and pictures, etc.When the user moves the handset to his/her ear, there may be less needto support multimedia functions, and the resources previously used tosupport these functions may be reallocated to higher quality audio(i.e., voice) communication. The resources may be reallocated back tomultimedia functions when the user moves the handset away from his/herear.

In block 802 of embodiment method 800, a first mobile device 102, suchas mobile device 102 in FIG. 1, may establish a communication channelwith at least one other (i.e., second) mobile device, such as device(s)104, 106, and/or 108 in FIG. 1, using a first communicationinfrastructure. The first mobile device 102 may communicate with the atleast one second mobile device using the first communicationinfrastructure in block 804. The device 102 may be in a first position202 such as shown in FIG. 2. The first mobile device 102 may detect amotion of the device corresponding to the user bringing the handset tohis/her ear in block 806. The detected motion may be the motioncorresponding to a transition between the first position 202 and thesecond position 204, indicated by dashed line 222 in FIG. 2. In responseto this detected motion, the device may transition to a secondcommunication infrastructure in block 808. The first mobile device 102may communicate with the at least one second mobile device using thesecond communication infrastructure at block 810. The first mobiledevice 102 may detect a motion of the device corresponding to the usermoving the device handset away from his/her ear in block 812. Thedetected motion may be the motion corresponding to a transition betweenthe second position 204 and the first position 202, indicated by dashedline 224 in FIG. 2. In response to this detected motion, the device maytransition back to the first communication infrastructure in block 814.

FIG. 9 is a process flow diagram illustrating an embodiment method 900of modifying the operating mode of a mobile device in response to adetected movement of the device corresponding to the user placing themobile device on a surface. In embodiments, the detected movement ofplacing the mobile device on a surface may cause the device to enter anactive mode in which the device continues to participate in an activecommunication session while monitoring for the presence of the user inproximity to the device. While the user is holding the device handset(e.g., the handset is in the first position 202 shown in FIG. 2), it maybe assumed that the user intends to actively participate in the groupcommunication session, or at the very least is in a position to listento incoming audio. However, when the user places the handset down on asurface (e.g., the handset is in the third position 206 shown in FIG.2), it may be the case that the user is still listening/participating inthe communication session. However, it may also be the case that theuser has become distracted, is on another call using another device, hasleft the room, etc.—i.e. is no longer participating in the call. Invarious embodiments, when the mobile device detects that it has beenplaced on a surface, the device may monitor for the presence of the userand continue the communication in an active mode so long as the user isdetected nearby. When the user is not detected, the device may inferthat the user is not paying attention to the call anymore, and may takean appropriate action, such as muting the incoming audio feed,buffering/recording the incoming talk spurts, notifying the otherdevices that the user of the first device may not be listening, and/orterminating the communication session.

In block 902 of embodiment method 900, a first mobile device 102, suchas mobile device 102 in FIG. 1, may communicate with at least one other(i.e., second) mobile device, such as device(s) 104, 106, and/or 108 inFIG. 1, in a group communication session. The first mobile device 102may detect a motion of the device corresponding to a placement of thedevice on a stable surface in block 904. The detected motion may be themotion corresponding to a transition between the first position 202 andthe third position 206, indicated by dashed line 222 in FIG. 2. In someembodiments, the device may discriminate between the user putting thedevice down on stationary surface and the user putting the device downon a moving surface, such as when the device is in a moving vehicle, inwhich case it may be assumed that the user is still paying attention tothe communication session. In embodiments, the device may alsodifferentiate between the user putting the device down “face-up”(illustrated by the third position 206 in FIG. 2) and putting the devicedown “face-down” (illustrated by the fourth position 208 in FIG. 2),which may cause the device to enter a separate operating mode describedin further detail below. In other embodiments, the device may notdifferentiate between a “face-up” and a “face-down” orientation.

In response to the detected motion of the device in block 904, themobile device 102 may enter an active mode in which the device maintainsactive in the communication session in block 906. When in the activemode, the device 102 may monitor for the presence of the user inproximity to the device in block 908. To determine the presence of theuser, the device may use any suitable technique for inferring thepresence of the user, such as the user picking up or moving the device,biometric detection techniques, voice recognition, etc.

While the device detects the presence of the user (i.e., determinationblock 910=“Yes”), the device 102 may remain in active mode in block 906and may continue to monitor for the presence of the user in block 908.When the user is not detected (i.e., determination block 910=“No”), thedevice 102 may wait a predetermined timeout period. During the timeoutperiod (i.e., determination block 912=“No”), the device may continue tomonitor for the user in block 908. If the user is detected, the devicemay remain in active mode and re-set the timeout period. Upon theexpiration of the timeout period (i.e., determination block 912=“Yes”)the device 102 may enter a non-active communication mode in block 914.

In embodiments, when the device 102 enters a non-active communicationmode, it may be inferred that the user is no longer listening to orparticipating in the group communication session. Upon entering thenon-active communication mode, the device 102 may mute or otherwisesuppress the incoming audio and/or video feed. Optionally, the firstmobile device 102 may send a message to the at least one second mobiledevice to indicate that the first mobile device 102 is in a non-activecommunication mode in block 916. Thus, the other participants in thesession may be informed that the user of the first mobile device 102 maynot be paying attention to the call. In an embodiment, suppressingcommunication may involve suspending forced audio messages from theother mobile devices in the group. The device 102 optionally may providefeedback to the user that the device is entering non-activecommunication mode (e.g., the device may provide a beep or audio tone,the display screen or an indicator light may flash yellow, etc.). Thedevice 102 may remain in a non-active communication mode in block 918.Optionally, while the device is in non-active communication mode, thedevice may buffer or otherwise record incoming voice and/or other datafor later playback in optional block 920. The device 102 may continue tomonitor for the presence of the user in block 922. Thus, if for examplethe user has stepped out of the room and returns while the device is innon-active communication mode, the device may detect the presence of theuser (i.e., determination block 924=“Yes”), and the device may resumethe communication session in an active mode in block 930.

In embodiments, the device 102 may remain in a non-active communicationmode for a pre-determined timeout period. The timeout period may be thesame as or different than the timeout period while the device is inactive mode. In embodiments, either or both timeout periods may be setor modified by the user. During the timeout period (i.e., determinationblock 926=“No”) the device may remain in a non-active communicationmode, monitoring for the presence of the user and optionally bufferingor recording incoming communications. After the expiration of thetimeout period (i.e., determination block 926=“Yes”), assuming theuser's presence has not been detected (i.e., determination block924=“No”), the device 102 may end the communication session in block928.

It will be noted that while the device is in active mode or non-activecommunication mode as described above, the device 102 may detect amotion of the device handset corresponding to the user picking up thehandset from the surface (e.g., the motion indicated by dashed line 230in FIG. 2), and the detection of this motion may be sufficient to returnthe device to a normal communication mode (such as the public modeand/or private mode described above).

FIG. 10 is a process flow diagram illustrating an embodiment method 1000of modifying the operating mode of a mobile device in response to adetected motion of the device corresponding to the user placing themobile device face-down on a surface. Embodiment method 1000 is similarto embodiment method 900 described above, except that in this method thedetected movement of placing the mobile device handset “face down” on asurface may cause the device to directly enter a non-activecommunication mode. By the action of the user placing the handset facedown on a surface (e.g., the handset is moved to the fourth position 208shown in FIG. 2), it may be inferred that the user no longer wishes toparticipate in the communication session. The device may thus enter anon-active communication mode and take appropriate action, such asmuting the incoming audio feed, buffering/recording the incoming talkspurts, notifying the other devices that the user of the first devicemay not be listening, and/or terminating the communication session.

In block 1002 of embodiment method 1000, a first mobile device 102, suchas mobile device 102 in FIG. 1, may communicate with at least one other(i.e., second) mobile device, such as device(s) 104, 106, and/or 108 inFIG. 1, in a group communication session. The first mobile device 102may detect a motion of the device corresponding to a placement of thedevice face down on a surface in block 1004. The detected motion may bea motion indicated by dashed lines 222 or 232 in FIG. 2.

In response to the detected motion in block 1002, the device 102 mayenter a non-active communication mode in block 1006. In embodiments,when the device 102 enters a non-active communication mode, it may beinferred that the user no longer intends to participate in the groupcommunication session. Upon entering the non-active communication mode,the device 102 may mute or otherwise suppress the incoming audio and/orvideo feed. Optionally, the first mobile device 102 may send a messageto the at least one second mobile device to indicate that the firstmobile device 102 is in a non-active communication mode in block 1008.Thus, the other participants in the session may be informed that theuser of the first mobile device 102 does not intend to continue thesession. In an embodiment, suppressing communications may involvesuspending forced audio messages from at least one other mobile device.The device 102 may remain in a non-active communication mode in block1010. As in the embodiment method 900 of FIG. 9, while the device is inthe non-active communication mode, the device may buffer or otherwiserecord incoming voice and/or other data for later playback.

The device 102 may remain in a non-active communication mode for apre-determined timeout period (i.e., determination block 1014=“Yes”).The timeout period may be the same as or different than the timeoutperiods described above in connection with embodiment method 900. Ingeneral, the timeout period in embodiment method 1000 may be relativelyshort (e.g., 5-10 seconds, optionally less than 5 seconds, such as 1-2seconds or less), since the placement of the device handset in a facedown position may indicate that the user does not wish to continue thecommunication session. However, the user may have inadvertently placedthe device in a face down position, and the timeout period may give theuser an opportunity to exit the non-active communication mode and resumethe communication session. As shown in FIG. 10, for example, while thedevice is in the non-active communication mode, the device may determinewhether the device has been moved. If the device has been moved (i.e.,determination block 1012=“Yes”), then the device may exit the non-activecommunication mode and resume the communication in block 1018. In someembodiments, any detected movement of the device 102 during thenon-active communication mode may be sufficient to exit the non-activecommunication mode and return to the communication session. In otherembodiments, the non-active communication mode may be exited by pickingup the handset from the surface (e.g., the motion indicated by dashedline 230 in FIG. 2) and/or by turning the handset over to a “face-up”position (e.g., the motion indicated by dashed line 236 in FIG. 2).

FIG. 11A is a process flow diagram illustrating an embodiment method1100 of voice activated half-duplex (e.g., Push to Talk) communicationusing a mobile device. In this embodiment, the mobile device may detecta voice command of a user and in response may send the command to aserver, such as the group communication server 120 shown in FIG. 1. Invarious embodiments, the command may be request to the server forcontrol of the “floor” in a half-duplex group communication session.

In block 1102 of embodiment method 1100, a first mobile device, such asmobile device 102 in FIG. 1, may communicate with at least one other(i.e., second) mobile device, such as device(s) 104, 106, and/or 108 inFIG. 1, in a group communication session. The group communicationsession may be a half-duplex communication session, such as aPush-to-Talk communication session. The group communication session maybe under the control of a central server, such as group communicationserver 120 shown in FIG. 1. The server 120 may arbitrate control of the“floor” for half-duplex communication between the mobile devicesparticipating in the communication session (i.e., the communicationgroup).

The first mobile device 102 may monitor external audio signals in block1104. In embodiments, the device 102 may use the device's microphone to“listen” for certain external sounds, such as the voice of a user of thedevice. The device 102 may monitor the external audio when the device isnot actively transmitting voice data (i.e., when the device has not beengranted the “floor”). The first mobile device 102 may determine whethera detected audio signal is a recognized voice command to a groupcommunication server in block 1106. In some embodiments, this mayinclude analyzing the detected audio signal (e.g., using voicerecognition software) to determine if it corresponds to a command to thegroup communication server. In embodiments, the first mobile device 102may analyze the detected audio signal for particular keyword(s)associated with a command, for example. In other embodiments, the firstmobile device 102 may simply listen for the sound of the user's voice,and when the user's voice is detected the device 102 may transmit theaudio signal to the group communication server 120. The server mayinclude functionality to analyze and interpret the transmitted voicecommand. In embodiments, the first mobile device 102 may detect thesound of the user's voice, and if the voice is detected above apre-determined threshold volume, the device will treat the detectedvoice signal as a voice command to the group communication server.

The first mobile device 102 may continue to monitor external audiosignals when no recognized voice command is detected (i.e.,determination block 1108=“No”). When the first mobile device 102 detectsa voice command (i.e., determination block 1108=“Yes”), the device maytransmit the command to the group communication server 120 in block1110. As discussed above, in some embodiments the first mobile device102 may analyze and interpret the voice command, using voice recognitionsoftware for example, and prior to transmitting the command, convert thesignal into an appropriate data format that may be recognized by theserver. In other embodiments, the mobile device 102 may simply relay thevoice command from the user to the server, where the server may analyzeand interpret the voice command. The first mobile device 102 mayoptionally provide feedback to the user that a voice command has beenreceived at the device 102 and forwarded to the server 120.

The voice command may be any command used in a group communicationsession, such a command to commence a communication session with aparticular communication group, to terminate the session, to add or dropgroup members from a communication session, to send or download mediafiles, and so forth. In particular, the voice command may be a commandto request the floor in a group communication session. In someembodiments, the detection of the user speaking (optionally above athreshold volume level) may be sufficient to cause the mobile device 102to request control of the floor from the group communication server 120.In embodiments, the user may simply begin speaking without waiting forfloor access. Upon detection of the user's voice, the mobile device 102may transmit a request for the floor and buffer or otherwise record theuser's message while waiting for floor access. When floor access isgranted by the server, the device 102 may transmit the buffered messageto the communication group. In other embodiments, the user mayexplicitly request the floor using a voice command (e.g., “floor,” “Iwant the floor,” etc.), and then wait until the server grants the floorbefore transmitting his/her message. In contrast to some half-duplexgroup communication systems, which may require a user to repeatedlyrequest the floor (such as by pressing a Push-to-Talk button) until thefloor is open, embodiments of the present voice activated groupcommunication method and system may enable the user to request the flooronce, via a voice command, and then wait for the floor to be granted bythe group communication server 120. The first mobile device may receivea response message from the group communication server 120 indicatingthe floor has been granted to the user's device in block 1112, and thefirst mobile device 102 may transmit voice and/or other data to the atleast one second mobile device in block 1114. The first mobile device102 may optionally provide feedback to the user that the floor has beengranted by the server.

When the user is finished speaking, the user may relinquish the floorusing any suitable means, such as by pressing a button or key on a userinterface, or by touching a touchscreen interface. In embodiments, thefloor may be relinquished using a voice command (e.g., a particularkeyword or keyword string, not likely to be used in regularconversation). FIG. 11B is a process flow diagram illustrating anembodiment method 1101 in which the mobile device may detect when theuser has finished speaking (i.e., when the user is silent), and based onthe detected silence the device may relinquish control of the floor. Thefirst mobile device 102 may receive external audio signals, such as theuser's voice, in block 1116, and transmit the signals (e.g., voice data)over the group communication channel to at least one second mobiledevice in block 1118. While the mobile device 102 continues to detectexternal sound (i.e., determination block 1120=“No”), the device 102 maycontinue to transmit the voice data to the other device(s) in block1116. When the device 102 detects silence (i.e., determination block1120=“Yes”), the detected silence may trigger the start of a timeoutperiod. The timeout period may have a duration that is sufficient toinfer that the user has finished speaking and would like to relinquishcontrol of the floor (e.g., generally around 1 second or more). Duringthe timeout period (i.e., determination block 1122=“No”), the device maycontinue to monitor for external audio signals, and if such signals aredetected (i.e., determination bock 1120=“No”), the device may continueto transmit the signals in block 1118 and restart the timeout periodwhen the device next detects silence. When the timeout period expires(i.e., determination block 1122=“Yes”), the device 102 may close thecommunication channel in block 1124 and send a message to the groupcommunication server relinquishing control of the floor in block 1126.

FIG. 11C is a process flow diagram illustrating an embodiment method1103 of controlling floor access for a plurality of mobile devices by aserver. In this embodiment method 1103, the server, which may be a groupcommunication server 120 shown in FIG. 1, may receive audio voicemessages from the mobile devices and analyze the messages to detectrequests for action (i.e., voice commands) from the users of the mobiledevices. The server may then process the requests as appropriate. In oneaspect, the requests may include requests for floor access by thevarious mobile devices in a group communication session. The server mayprocess the requests by scheduling floor access (e.g., “queuing” up therequesting devices for available floor times) during the groupcommunication session. The server may send messages to the mobiledevices indicating the status of the floor control for the session. Themessages may be sent when the floor is granted to the particularrequesting device and/or may be sent to indicate when the device is nextscheduled for floor access.

In block 1128 of embodiment method 1103, the server 120 may initiate agroup communication session between two or more mobile devices. Thegroup communication session may be initiated and operated similar to anyconventional half-duplex group communication session, such as aconventional Push-to-Talk session. The server 120 may receive audiovoice messages from the mobile devices in the group communicationsession in block 1130. The audio voice messages may include voicecommands from users of the mobile devices. In block 1132, the server 120may interpret the voice messages to determine the particular requestsfor action by the server in the respective voice messages. The requestsfor action may include requests for access to the floor in the groupcommunication session, for example. The server 120 may schedule flooraccess for the requesting mobile devices in response to the receivedrequests for action in block 1134. In block 1136, the server 120 maysend messages to the mobile devices indicating the status of floorcontrol. The messages may inform the respective devices that, forexample, the floor request is granted, the floor request is not granted,or that the device is scheduled for floor access at a later time.

Various embodiments include methods and systems of communicating using afirst mobile device that include establishing a new communicationchannel with at least one other (i.e., second) mobile device in responseto a detected motion of the first device. FIG. 12 illustrates anembodiment method 1200 for establishing a new communication channel withat least one second mobile device in response to a detected motion of afirst mobile device. In block 1202 of embodiment method 1200, a firstmobile device 102, may detect a motion of the device corresponding to aparticular user action. The detected motion may be any movement orchange in position or orientation of the device that may be correlatedto a particular action by the user. For example, the detected motion maybe any of the motions schematically illustrated in FIG. 2, such as themotion of the user bringing the device towards or away from his/her ear.The detected motion may also be a “flicking” motion, a shaking motion,etc. In some embodiments, the detected motion may be the rotation of thedevice handset, such as the user rotating the handset by 90°, by 180°,or by any arbitrary amount.

The mobile device 102 may be configured with accelerometers andgyroscopes, as are common in many smartphones, and the processor may beconfigured to monitor such sensors in block 1202 to determine when suchsensor outputs match thresholds and/or patterns in memory correlated toparticular actions. In an embodiment, mobile device motion measurementscorrelated to particular user actions may be defined by the user, suchas via a menu interface and/or a training routine. Thus, operations thatare encompassed in block 1202 (as well as blocks 1302, 1402, 1502, 1602and 1610 discussed below) may include continuously monitoringaccelerometer, gyroscope and/or other motion sensors when in an activestate, and comparing sensor data received from such sensors within asampling interval to patterns of motion sensor data stored in memorycorrelated to particular actions or commands. When a match is detected,the mobile device processor may initiate the action correlated to thematched pattern. In the various embodiments, that action may includeestablishing a new communication link and proceeding as described below.

In response to detecting a motion correlated to ensuring continuity ofcommunications, the first mobile device may establish a newcommunication channel with at least one other (i.e., second) device,such as device(s) 104, 106, 108 in FIG. 1, in block 1204. In someembodiments, the first device 102 may have already established aninitial communication channel, either a synchronous or asynchronouscommunication channel, with the at least one second mobile device, andin response to the detected motion, the first mobile device mayestablish a new communication channel with the second device. Forexample, the first mobile device 102 may be communicating with the atleast one second mobile device using asynchronous messaging (e.g., SMSor e-mail), and in response to the detected motion may establish asynchronous communication channel with the at least one second mobiledevice. In other embodiments, the devices may be communicating over onetype of synchronous communication channel (e.g., a half-duplex voicechannel) and in response to the detected motion, the first mobile devicemay establish a different synchronous communication channel (e.g., afull-duplex voice channel or video channel). In other embodiments, thedevices may initially not be communicating at all, and the first mobiledevice may establish a communication channel (e.g., initiate aphone/video call) with the at least one second mobile device in responseto the detected motion. In another embodiment, the first mobile devicemay be participating in a half-duplex or Push-to-talk groupcommunication session with the at least one second mobile device, and inresponse to the detected motion the first mobile device may establish anew communication channel by requesting the “floor” from a centralserver. In block 1206, the first mobile device 102 may communicate withthe at least one second mobile device over the new communicationchannel.

In optional block 1208, the first mobile device may detect a secondmotion of the mobile device correlated to terminating a redundantchannel or otherwise exiting a communication mode, and in response tothe detected second motion may close the new communication channel withthe at least one second mobile device in optional block 1210. Forexample, the first detected motion may be the motion of the userbringing the device to his/her ear and the detected second motion may bethe motion of the user moving the device away from his/her ear.Alternatively, the first detected motion may be the motion of the usermoving the device away from his/her ear, and the detected second motionmay be the motion of the user moving the device towards his/her ear. Thedetected second motion may be any movement or change in position ororientation of the device that may be performed by the user, such asplacing the mobile device on a surface, removing the device from asurface, a “flicking” motion, a shaking motion, a rotational motion ofthe device, etc.

In various embodiments, closing the new communication channel inoptional block 1210 may terminate the communication session with the atleast one second mobile device. In other embodiments, when the newcommunication channel is closed in optional block 1210, the first devicemay continue the communication session with the at least one secondmobile device by transitioning to a different communication channel,which may be a previous communication channel used by the first mobiledevice for communicating with the at least one second mobile device.

FIG. 13 illustrates a further embodiment method 1300 for establishing anew communication channel with at least one other (i.e., second) mobiledevice in response to recognizing a particular motion of a first mobiledevice. In block 1302, a first mobile device 102 may communicate with atleast one second mobile device, such as device(s) 104, 106, 108 in FIG.1, over an initial communication channel. The initial communicationchannel may be an asynchronous communication channel (e.g., SMS ore-mail) or a synchronous communication channel (e.g., a half-duplex orfull-duplex voice channel, a video channel, etc.). In block 1304, thefirst mobile device may detect a motion of the device corresponding to aparticular user action. The detected motion may be any movement orchange in position or orientation of the device that may be correlatedto a particular action by the user, such as any of the motionsschematically illustrated in FIG. 2 (e.g., moving the device to or fromthe user's ear, placing the mobile device on a surface), a “flicking”motion, a shaking motion, a rotation of the device handset, etc.

In response to the detected motion, the first mobile device mayestablish a new communication channel with the at least one secondmobile device in block 1306. The new communication channel may be adifferent communication channel than the initial communication channel.For example, the initial communication channel may be an asynchronouscommunication channel and the new communication channel may be asynchronous communication channel. For example, the first mobile devicemay be communicating with at least one second mobile deviceasynchronously (such as via SMS or “texting”), and in response to thedetected motion, which may be a movement of the device to the user'sear, for instance, the first device may establish a new synchronouscommunication channel with the at least one second mobile device. Thenew synchronous communication channel may be a half-duplex orfull-duplex voice channel or a video channel, for example. In otherembodiments, the initial communication channel may be a firstsynchronous communication channel, and the new communication channel maybe a different synchronous communication channel. For example, thedetected motion of the device may cause the device to transition betweenhalf-duplex and full-duplex communication channels, such as describedabove in connection with FIGS. 6A and 6B. In other embodiments, adetected motion of the mobile device, such as shaking or “flicking” thedevice, rotating the device handset by 90°, 180°, or by any arbitraryamount, etc., may cause the device to transition between a synchronousvoice communication channel (e.g., half- or full-duplex) and asynchronous multimedia communication channel (e.g., video telephony),and vice versa. In block 1308, the first device may communicate with theat least one second mobile device over the new communication channel.

FIG. 14 illustrates a further embodiment method 1400 for establishing anew communication channel with at least one other (i.e., second) mobiledevice based on a detected motion of a first mobile device. In block1402 of embodiment method 1400, a first mobile device 102 may detect amotion of the device corresponding to a particular user action. Thedetected motion may be any movement or change in position or orientationof the device that may be correlated to a particular action by the user.For example, the detected motion may be any of the motions schematicallyillustrated in FIG. 2, such as the motion of the user bringing thedevice towards or away from his/her ear. The detected motion may also bea “flicking” motion, a shaking motion, etc. In some embodiments, thedetected motion is the rotation of the device handset, such as the userrotating the handset by 90°, by 180°, or by any arbitrary amount.

In block 1404, the first mobile device may determine at least one secondmobile device based on the user interface context presented to the userof the first mobile device. The user interface may be a display screen,such as a touchscreen interface, which may display text and/or graphicalelements to the user. In embodiments, a unique identifier (e.g., phonenumber, URL, etc.) associated with the at least one second mobiledevice, and useable for establishing a communication channel with the atleast one second mobile device, may be stored on the first mobile device(e.g., in a stored contact list). The first mobile device may determinethe at least one second mobile device by associating one or moretextual/graphical elements displayed on the user interface with aparticular device or devices stored in the first mobile device's storedcontacts. In some embodiments, the first mobile device may determine theat least one second mobile device based on a unique identifier (e.g.,phone number, URL, etc.) for the device being displayed on the userinterface (e.g., on a web page, e-mail, vCard, etc.), whether or not thedevice associated with the identifier is already stored in the firstdevice's contact list.

There are various ways in which the first mobile device may extrapolatethe identity of one or more second mobile devices with which the userintends to connect to from the user interface context presented to theuser. In various embodiments, the first mobile device may identify atleast one second mobile device when, for example, one or more contactsassociated with another mobile device is highlighted or selected on theuser interface. In embodiments, the first mobile device may identify atleast one second mobile device when a conversation window is displayedthat implies that the user is in conversation with one contact or withmore than one contact (i.e., a group of contacts). In embodiments, theconversation window may be a means to identify at least one other devicebased on a conversation window being displayed on the screen, where theconversation window may be a scrollable region of the display thatcontains an ongoing conversation with another user. If the user of thefirst mobile device 102 has a conversation window on screen when themotion is detected (block 1402), then the first device may infer that anew communication channel should be initiated with at least one secondmobile device associated with the user or users represented in theconversation window. In embodiments, the first mobile device mayidentify at least one second mobile device when a photograph of acontact (e.g., a user of a stored contact device) is displayed and/orwhen a video of a contact is displayed. The first mobile device mayidentify particular individuals depicted in a multimedia file (e.g., aphoto or video) through metadata, such as “tagging” data, associatedwith the file and/or via facial or voice recognition software. Inembodiments, the first mobile device may identify at least one secondmobile device when a calendar event is displayed that is common with oneor more contacts. In embodiments, the first mobile device may identifyat least one second mobile device when a particular location, such as amap location, is displayed, where the at least one second mobile deviceis known to be at the particular location.

The first mobile device may establish a new communication channel withthe at least one second mobile device in block 1408. The newcommunication channel may be an asynchronous communication channel or asynchronous communication channel, such as a half-duplex or full-duplexvoice channel, a video channel, a streaming touchpoints channel, etc. Asused herein, “touchpoints” is a feature name for the ability for a userto press or touch on certain regions of media content (e.g., synchronoussession with another user that has the same media content displayed onhis/her screen on a second device, where the region that is touched onthe first device may be animated or otherwise indicated on the seconddevice. For example, if the first user touches the upper left handportion of a picture, the second user may see an animation or otherindication in the upper left hand portion of the same picture on his/herdevice.

In some embodiments, before establishing the new communication channel,the first mobile device may determine the type of the new communicationchannel to establish based on the detected motion, the user interfacecontext, or both, in optional block 1406. For example, if the detectedmotion corresponds to the user bringing the device handset to his/herear, then the new communication channel may be a voice channel, such asa full-duplex voice channel. On the other hand, if the detected motioncorresponds to the user bringing the handset in front of his/her face,then the new communication channel may be a half-duplex (e.g.,Push-to-Talk) voice channel or a video channel. In addition, the firstmobile device may determine the type of communication channel toestablish based on the user interface context being presented to theuser. For example, if the user interface displays a call history screenwith a particular contact highlighted, then the first mobile device mayinfer that the new communication channel should be a voice call. If theuser interface displays a video clip in which a particular contact ispresent, then the first mobile device may infer that the newcommunication channel should be a video call. If the user interfacedisplays a photo of the contact, then the first mobile device may inferthat the new communication channel should be a “touchpoints call,” andso forth. As discussed above, a “touchpoints” call may include aconversation or session through which two or more users may share mediacontent, such as a picture, video, slide presentation, etc., and which auser may visually indicate portions or features of the content onanother user's device.

In embodiments, the type of new communication channel to establish mayalso be determined based on prior communication sessions with the atleast one second communication device. For example, if the lastcommunication session with a particular contact was a video chat, thenthe first mobile device may infer that the new communication channelwith the same contact should be a video channel.

FIG. 15 illustrates an embodiment method 1500 for group communicationwith a mobile device in which a communication session may be paused orsuspended based on a detected motion of the mobile device. Operationsperformed in blocks 1502-1506 of embodiment method 1500 may be similarto the operations in blocks 1202-1206 of embodiment method 1200described above with reference to FIG. 12. These operations may includedetecting a first motion of the first mobile device correlated to afirst user action (block 1502), in response to the detected motion,establishing a new communication channel with at least one second mobiledevice (block 1504), and communicating with the at least one secondmobile device over the new communication channel (block 1506). In block1508, the first mobile device may detect a second motion of the devicecorrelated to a second user action. The detected second motion may beany movement or change in position or orientation of the device that maybe correlated to a particular action by the user, such as the userpulling the device away from his/her ear, placing the mobile deviceface-up or face-down on a surface, “flicking,” shaking or rotating thedevice, etc. Upon detecting the second motion, the first mobile devicemay be maintained in a non-active communication mode in block 1510. Uponentering the non-active communication mode, the device may silence thespeaker, mute the microphone and/or otherwise suppress incoming and/oroutgoing communications with the at least one second mobile device.Suppressing communication at the mobile device may involve suspendingforced audio messages from the at least one second mobile device.

The mobile device may remain in a non-active communication mode for apre-determined timeout period (i.e., while determination block1514=“No”). The timeout period may be variable, and in some embodimentsmay be programmable by the user. In general, the timeout period inembodiment method 1500 may be relatively short (e.g., 1 minute or less,such as 5-30 seconds, optionally less than 5 seconds, such as 1-2seconds or less), since the detected second motion may indicate that theuser does not wish to continue the communication session. However, theuser may have inadvertently or temporarily moved the device, with theintent to resume or continue the communication session, so the timeoutperiod may provide the user an opportunity to exit the non-activecommunication mode and resume the communication session. As shown inFIG. 15, for example, while the mobile device is in a non-activecommunication mode, a processor of the device may determine whether thedevice has been moved. If the mobile device has been moved (i.e.,determination block 1512=“Yes”), the device processor may determinewhether the detected motion corresponds to the first user action inblock 1518. For example, the detected motion may correspond to the usermoving the device towards his or her ear, indicating an intent tocontinue the communication. If the detected motion is correlated to thefirst user action (i.e., determination block 1520=“Yes”), the mobiledevice may resume the communication over the communication channel inblock 1522. If the detected motion is not correlated to the first useraction (i.e., determination block 1520=“No”), then the device may bemaintained in the non-active communication mode in block 1510. If thedevice is not moved (i.e., determination block 1512=“No”) and thetimeout period expires (i.e., determination block 1514=“Yes”), then thecommunication channel may be closed in block 1516.

Various embodiments include methods and system for initiating and/orcontrolling a half-duplex communication session based on the detectedmotion of the mobile device handset. In such embodiments, a first mobiledevice may detect a first motion and in response to the detected motion,the device may initiate or launch a half-duplex group communicationapplication, such as a Push-to-Talk (PTT) application. For example, theuser may be conducting asynchronous messaging with at least one secondmobile device and by rotating the handset by a pre-determined amount(e.g., 180°), the device may automatically initiate a half-duplex groupcommunication session. The detected first motion may trigger a change inthe user interface context (i.e., the device may display icons or othervisual feedback associated with half-duplex communication, such as a“virtual” PTT button), and in some embodiments, may automaticallyrequest the “floor” for group communication with at least one secondmobile device.

FIG. 16A illustrates an embodiment method 1600 for initiating ahalf-duplex communication session based on the detected motion of amobile device. In block 1602, a first mobile device 102 may detect amotion of the device corresponding to a particular user action. Asdiscussed above, the detected motion may be any movement or change inposition or orientation of the device that may be correlated to aparticular action by the user. For example, the detected motion may beany of the motions schematically illustrated in FIG. 2, such as themotion of the user bringing the device towards or away from his/her ear.The detected motion may also be a “flicking” motion, a shaking motion,etc. In some embodiments, the detected motion may be the rotation of thedevice handset, such as the user rotating the handset by 90°, by 180°,or by any arbitrary amount.

In response to the detected motion, the first mobile device 102 mayinitiate a half-duplex group communication application (e.g., a PTTapplication) in block 1604. The device may display visual feedbackassociated with the half-duplex communication on a display screen of themobile device in block 1606. In an embodiment, the detected motion ofthe device handset may cause a change in a user interface context, suchthat the device may display icons or other visual feedback associatedwith half-duplex communication, such as a “virtual” PTT button. Thedevice 102 may display contact information, such as name(s), icon(s),photograph(s), etc., associated with at least one other (i.e., second)mobile device that forms a communication group (e.g., PTT group) withthe first mobile device 102. In some instances, the first mobile devicemay be communicating with at least one other mobile device over aninitial communication channel, such as an asynchronous channel, andbased on the detected motion of the device, the first mobile device mayinitiate a half-duplex communication session with the at least onesecond mobile device. The of the user interface context may change toindicate that the first mobile communication device is now in ahalf-duplex group communication session with the at least one secondmobile device.

In some embodiments, in response to the detected motion, the firstmobile device may initiate a half-duplex communication session with thelast communication group with which the first mobile device waspreviously engaged in a half-duplex communication session. The of theuser interface context may change to indicate that the first mobiledevice is now in a group communication session with this communicationgroup.

In some embodiments, in response to the detected motion, the firstmobile device may initiate a half-duplex communication session with atleast one other mobile device based on the of the user interface contextat the time the half-duplex communication session is initiated. Forexample, the user may scroll through, highlight or otherwise display oneor more contacts on the user interface, and based on the detectedmovement of the first device, a group communication session may beinitiated with the mobile device(s) associated with these contact(s). Insome embodiments, the user interface may display a photograph, video orother media file containing one or more contacts, or a web-page or othergraphical/textual elements associated with one or more contacts, andbased on the detected movement of the first device, a groupcommunication session may be initiated with the mobile device(s)associated with these contact(s). The of the user interface context maychange to indicate that the first mobile device is now in a groupcommunication session with the mobile device(s) associated with thesecontact(s).

In some embodiments, the detected first motion may cause the firstmobile device 102 to automatically request the “floor” for communicationwith the at least one second mobile device, as shown in optional block1608.

FIG. 16B illustrates an embodiment method 1601 for initiating andcontrolling a half-duplex communication session based on the detectedmotion of a mobile device. Blocks 1610-1614 of embodiment method 1601are similar to blocks 1602-1606 of embodiment method 1600 shown in FIG.16A, and may include detecting a first motion of a first mobile devicecorresponding to a first user action (block 1610), in response to thedetected first motion, initiating a half-duplex group communicationapplication (block 1612), and displaying visual feedback associated withthe half-duplex communication on a display screen of the first mobiledevice (block 1614). In block 1616, the first mobile device may detect asecond motion of the first mobile device. In response to the detectedsecond motion, the first mobile device may request the floor for groupcommunication with at least one other device. For example, the firstdetected motion may be a rotation of the device handset, such as by 90°,180°, or by any arbitrary amount, which may initiate the half-duplexgroup communication application. A further detected rotation of thedevice handset, such as by 90°, 180°, or by any arbitrary amount, maytrigger the device to request the floor for half-duplex communication.

In block 1620, the first mobile device may detect a third motion of themobile device. In response to the detected third motion, the firstmobile device may release control of the floor in the groupcommunication session in block 1622. For example, the detected secondmotion may be a rotation of the handset, which causes the device torequest the floor, and a detected third motion, such as a rotation ofthe handset back to its previous orientation, may trigger a release ofthe floor.

In optional bock 1624, the first mobile device may detect a fourthmotion of the mobile device. In response to the detected fourth motion,the device may establish a full-duplex communication channel with the atleast one second mobile device in optional block 1626. For example, thedetected fourth motion may be a motion corresponding to the userbringing the device to his/her ear, which may trigger a transition froma half-duplex communication to a full-duplex communication.

In optional block 1628, the first mobile device may detect a fifthmotion of the device. In response to the detected fifth motion, thedevice may close the communication channel with the at least one secondmobile device. For example, the fifth motion may correspond to the userplacing the mobile device face-up or face-down on a surface, or anymotion that may indicate that the user intends to end the communicationsession.

FIG. 17 is a system block diagram of a mobile device suitable for usewith any of the embodiments. A typical mobile device 1700 may include aprocessor 1701 coupled to internal memory 1702, to a display 1703, andto a speaker 1708. Additionally, the mobile device 1700 may include anantenna 1704 for sending and receiving electromagnetic radiation thatmay be connected to a wireless data link and/or cellular telephonetransceiver 1705 coupled to the processor 1701. Mobile devices 1700typically also include menu selection buttons 1707 or rocker switchesfor receiving user inputs

The various embodiments may be implemented on the data transmission sideon any of a variety of commercially available server devices, such asthe server 2000 illustrated in FIG. 18. Such a server 2000 typicallyincludes a processor 2001 coupled to volatile memory 2002 and a largecapacity nonvolatile memory, such as a disk drive 2003. The server 2000may also include a floppy disc drive, compact disc (CD) or DVD discdrive 2004 coupled to the processor 2001. The server 2000 may alsoinclude network access ports 2006 coupled to the processor 2001 forestablishing data connections with a network 2012, such as a local areanetwork coupled to other broadcast system computers and servers. Servers2000 may also include operator interfaces, such as a keyboard 2008,pointer device (e.g., a computer mouse 2010), and a display 2009.

The processors 1701, 2001 may be any programmable microprocessor,microcomputer or multiple processor chip or chips that can be configuredby software instructions (applications) to perform a variety offunctions, including the functions of the various embodiments describedbelow. In some mobile receiver devices, multiple processors 2001 may beprovided, such as one processor dedicated to wireless communicationfunctions and one processor dedicated to running other applications.Typically, software applications may be stored in the internal memory1702, 2002, 2003 before they are accessed and loaded into the processor1701, 2001. The processor 1701, 2001 may include internal memorysufficient to store the application software instructions.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the steps of the various embodiments must be performed inthe order presented. As will be appreciated by one of skill in the artthe order of steps in the foregoing embodiments may be performed in anyorder. Words such as “thereafter,” “then,” “next,” etc. are not intendedto limit the order of the steps; these words are simply used to guidethe reader through the description of the methods. Further, anyreference to claim elements in the singular, for example, using thearticles “a,” “an” or “the” is not to be construed as limiting theelement to the singular.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the aspects disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

The hardware used to implement the various illustrative logics, logicalblocks, modules, and circuits described in connection with the aspectsdisclosed herein may be implemented or performed with a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general-purpose processor maybe a microprocessor, but, in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Alternatively, some steps ormethods may be performed by circuitry that is specific to a givenfunction.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored as one or moreinstructions or code on a non-transitory computer-readable storagemedium or non-transitory processor-readable storage medium. The steps ofa method or algorithm disclosed herein may be embodied in aprocessor-executable software module which may reside on anon-transitory computer-readable or processor-readable storage medium.Non-transitory computer-readable or processor-readable storage media maybe any media that may be accessed by a computer or a processor. By wayof example, and not limitation, such non-transitory computer-readable orprocessor-readable media may include RAM, ROM, EEPROM, FLASH memory,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that may be used to storedesired program code in the form of instructions or data structures andthat may be accessed by a computer. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk, and blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofnon-transitory computer-readable and processor-readable media.Additionally, the operations of a method or algorithm may reside as oneor any combination or set of codes and/or instructions on anon-transitory processor-readable medium and/or computer-readablemedium, which may be incorporated into a computer program product.

The preceding description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present invention.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of theinvention. Thus, the present invention is not intended to be limited tothe aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method of communication using a first mobiledevice, comprising: communicating with at least one second mobile devicein a public mode; detecting a first motion corresponding to a user ofthe first mobile device moving the first mobile device from a firstposition to a second position; transitioning from a public mode to aprivate mode in response to the detected first motion, whereintransitioning from the public mode to the private mode comprisesreallocating resources used for transmission, reception or display ofvisual media content to higher-quality audio communication; and sendinga message to the at least one second mobile device indicating atransition from the public mode to the private mode has occurred,wherein the first motion corresponds to the user moving the first mobiledevice to a position proximate the user's ear.
 2. The method of claim 1,wherein transitioning from a public mode to a private mode compriseschanging an audio path in the first mobile device from a speakerphonemode to an earpiece mode.
 3. The method of claim 1, further comprising:receiving a message from the at least one second mobile deviceindicating that the second mobile device has transitioned from thepublic mode to the private mode.
 4. The method of claim 1, furthercomprising: detecting a second motion corresponding to the user of thefirst mobile device moving the first mobile device from the secondposition to a third position; and transitioning from the private mode tothe public mode in response to the detected second motion.
 5. The methodof claim 4, wherein the second motion corresponds to the user moving thefirst mobile device away from his or her ear.
 6. The method of claim 4,further comprising: sending the message to the at least one secondmobile device indicating a transition from the private mode to thepublic mode.
 7. The method of claim 6, further comprising: receiving amessage from the at least one second mobile device indicating that thesecond mobile device has transitioned to the public mode.
 8. The methodof claim 7, further comprising: providing a feedback cue to the user ofthe first mobile device indicating that the second mobile device hastransitioned to the public mode.
 9. The method of claim 4, furthercomprising: suppressing communication at the first mobile device untilan indication of user compliance with the transition to the public modeis detected.
 10. A method of communication using a first mobile device,comprising: communicating with at least one second mobile device using afirst communication infrastructure; detecting a first motion of thefirst mobile device corresponding to a user moving the first mobiledevice from a first position to a second position; transitioning to asecond communication infrastructure in response to the detected firstmotion, wherein transitioning to the second communication infrastructurecomprises reallocating resources used for transmission, reception ordisplay of visual media content to higher-quality audio communication;and communicating with the at least one second mobile device using thesecond communication infrastructure, wherein the detected first motioncorresponds to the user moving the first mobile device to a positionproximate the user's ear.
 11. The method of claim 10, wherein thedetected first motion corresponds to the user moving the first mobiledevice to a position proximate the user's ear.
 12. The method of claim10, wherein transitioning to the second communication infrastructurecomprises switching between a 3G and a 4G network infrastructure. 13.The method of claim 10, further comprising: detecting a second motion ofthe first mobile device corresponding to the user moving the firstmobile device from the second position to the first position;transitioning to the first communication infrastructure based on thedetected second motion; and communicating with the at least one secondmobile device using the first communication infrastructure.
 14. A mobilecommunication device, comprising: a transceiver; and a processor coupledto the transceiver and configured with processor-executable instructionsto perform operations comprising: communicating with at least one secondmobile device in a public mode; detecting a first motion correspondingto a user of the mobile communication device moving the mobilecommunication device from a first position to a second position;transitioning from the public mode to a private mode in response to thedetected first motion, wherein transitioning from the public mode to theprivate mode comprises reallocating resources used for transmission,reception or display of visual media content to higher-quality audiocommunication; and detecting the first motion comprises detecting amotion corresponding to the user moving the mobile communication deviceto a position proximate the user's ear; sending a message to the atleast one second mobile device indicating a transition from the publicmode to the private mode has occurred, wherein detecting the firstmotion comprises detecting a motion corresponding to the user moving themobile communication device to a position proximate the user's ear. 15.The mobile communication device of claim 14, wherein the processor isconfigured with processor-executable instructions to perform operationssuch that transitioning from the public mode to a private mode compriseschanging an audio path in the mobile communication device from aspeakerphone mode to an earpiece mode.
 16. The mobile communicationdevice of claim 14, wherein the processor is configured withprocessor-executable instructions to perform operations furthercomprising: receiving a message from the at least one second mobiledevice indicating that the at least one second mobile device hastransitioned from the public mode to the private mode.
 17. The mobilecommunication device of claim 14, wherein the processor is configuredwith processor-executable instructions to perform operations furthercomprising: detecting a second motion corresponding to the user of themobile communication device moving the mobile communication device fromthe second position to a third position; and transitioning from theprivate mode to the public mode in response to the detected secondmotion.
 18. The mobile communication device of claim 17, wherein theprocessor is configured with processor-executable instructions toperform operations such that detecting the second motion comprisesdetecting a motion corresponding to the user moving the mobilecommunication device away from his or her ear.
 19. The mobilecommunication device of claim 17, wherein the processor is configuredwith processor-executable instructions to perform operations furthercomprising: sending the message to the at least one second mobile deviceindicating a transition from the private mode to the public mode. 20.The mobile communication device of claim 19, wherein the processor isconfigured with processor-executable instructions to perform operationsfurther comprising: receiving a message from the at least one secondmobile device indicating that the second mobile device has transitionedto the public mode.
 21. The mobile communication device of claim 20,wherein the processor is configured with processor-executableinstructions to perform operations further comprising: providing afeedback cue to the user of the mobile communication device indicatingthat the second mobile device has transitioned to the public mode. 22.The mobile communication device of claim 17, wherein the processor isconfigured with processor-executable instructions to perform operationsfurther comprising: suppressing communication at the mobilecommunication device until an indication of user compliance with thetransition to the public mode is detected.
 23. A mobile communicationdevice, comprising: a transceiver; and a processor coupled to thetransceiver and configured with processor-executable instructions toperform operations comprising: communicating with at least one secondmobile device using a first communication infrastructure; detecting afirst motion of the mobile communication device corresponding to a usermoving the mobile communication device from a first position to a secondposition; transitioning to a second communication infrastructure inresponse to the detected first motion, wherein transitioning to thesecond communication infrastructure comprises reallocating resourcesused for transmission, reception or display of visual media content tohigher-quality audio communication; and communicating with the at leastone second mobile device using the second communication infrastructure,wherein the detected first motion corresponds to the user moving themobile communication device to a position proximate the user's ear. 24.The mobile communication device of claim 23, wherein the processor isconfigured with processor-executable instructions to perform operationssuch that transitioning to the second communication infrastructurecomprises using a noise cancellation feature.
 25. The mobilecommunication device of claim 23, wherein the processor is configuredwith processor-executable instructions to perform operations such thattransitioning to the second communication infrastructure comprisesswitching between a 3G and a 4G network infrastructure.
 26. The mobilecommunication device of claim 23, wherein the processor is configuredwith processor-executable instructions to perform operations furthercomprising: detecting a second motion of the mobile communication devicecorresponding to the user moving the mobile communication device fromthe second position to the first position; transitioning to the firstcommunication infrastructure based on the detected second motion; andcommunicating with the at least one second mobile device using the firstcommunication infrastructure.
 27. A mobile communication device,comprising: means for communicating with at least one second mobiledevice in a public mode; means for detecting a first motioncorresponding to a user of the mobile communication device moving themobile communication device from a first position to a second position;means for transitioning from the public mode to a private mode inresponse to the detected first motion, wherein the means fortransitioning from the public mode to the private mode comprises meansfor reallocating resources used for transmission, reception or displayof visual media content to higher-quality audio communication; and meansfor sending a message to the at least one second mobile deviceindicating a transition from a public mode to the private mode hasoccurred, wherein the first motion corresponds to the user moving themobile communication device to a position proximate the user's ear. 28.The mobile communication device of claim 27, wherein means fortransitioning from the public mode to a private mode comprises means forchanging an audio path in the mobile communication device from aspeakerphone mode to an earpiece mode.
 29. The mobile communicationdevice of claim 27, further comprising: means for receiving a messagefrom the at least one second mobile device indicating that the secondmobile device has transitioned from the public mode to the private mode.30. The mobile communication device of claim 27, further comprising:means for detecting a second motion corresponding to the user of themobile communication device moving the mobile communication device fromthe second position to a third position; and means for transitioningfrom the private mode to the public mode in response to the detectedsecond motion.
 31. The mobile communication device of claim 30, whereinthe second motion corresponds to the user moving the mobilecommunication device away from his or her ear.
 32. The mobilecommunication device of claim 30, further comprising: means for sendingthe message to the at least one second mobile device indicating atransition from the private mode to the public mode.
 33. The mobilecommunication device of claim 32, further comprising: means forreceiving a message from the at least one second mobile deviceindicating that the second mobile device has transitioned to the publicmode.
 34. The mobile communication device of claim 33, furthercomprising: means for providing a feedback cue to the user of the mobilecommunication device indicating that the second mobile device hastransitioned to the public mode.
 35. The mobile communication device ofclaim 30, further comprising: means for suppressing communication at themobile communication device until an indication of user compliance withthe transition to the public mode is detected.
 36. A mobilecommunication device, comprising: means for communicating with at leastone second mobile device using a first communication infrastructure;means for detecting a first motion of the mobile communication devicecorresponding to a user moving the mobile communication device from afirst position to a second position; means for transitioning to a secondcommunication infrastructure in response to the detected first motion,wherein means for transitioning to the second communicationinfrastructure comprises means for reallocating resources used fortransmission, reception or display of visual media content tohigher-quality audio communication; and means for communicating with theat least one second mobile device using the second communicationinfrastructure, wherein the detected first motion corresponds to theuser moving the mobile communication device to a position proximate theuser's ear.
 37. The mobile communication device of claim 36, whereinmeans for transitioning to the second communication infrastructurecomprises means for using a noise cancellation feature.
 38. The mobilecommunication device of claim 36, wherein means for transitioning to thesecond communication infrastructure comprises means for switchingbetween a 3G and a 4G network infrastructure.
 39. The mobilecommunication device of claim 36, further comprising: means fordetecting a second motion of the mobile communication devicecorresponding to the user moving the mobile communication device fromthe second position to the first position; means for transitioning tothe first communication infrastructure based on the detected secondmotion; and means for communicating with the at least one second mobiledevice using the first communication infrastructure.
 40. Anon-transitory computer-readable storage medium having stored thereonprocessor executable instructions configured to cause a processor of afirst mobile communication device to perform operations comprising:communicating with at least one second mobile device in a public mode;detecting a first motion corresponding to a user of the first mobilecommunication device moving the first mobile communication device from afirst position to a second position; transitioning from the public modeto a private mode in response to the detected first motion whereintransitioning from the public mode to the private mode comprisesreallocating resources used for transmission reception or display ofvisual media content to higher-quality audio communication; and sendinga message to the at least one second mobile device indicating atransition from the public mode to the private mode has occurred,wherein detecting the first motion comprises detecting a motioncorresponding to the user moving the first mobile communication deviceto a position proximate the user's ear.
 41. The non-transitorycomputer-readable storage medium of claim 40, wherein the storedprocessor executable instructions are configured to cause the processorof the first mobile communication device to perform operations such thattransitioning from the public mode to a private mode comprises changingan audio path in the first mobile communication device from aspeakerphone mode to an earpiece mode.
 42. The non-transitorycomputer-readable storage medium of claim 40, wherein the storedprocessor executable instructions are configured to cause the processorof the first mobile communication device to perform operations furthercomprising: receiving a message from the at least one second mobiledevice indicating that the second mobile device has transitioned fromthe public mode to the private mode.
 43. The non-transitorycomputer-readable storage medium of claim 40, wherein the storedprocessor executable instructions are configured to cause the processorof the first mobile communication device to perform operations furthercomprising: detecting a second motion corresponding to the user of thefirst mobile communication device moving the first mobile communicationdevice from the second position to a third position; and transitioningfrom the private mode to the public mode in response to the detectedsecond motion.
 44. The non-transitory computer-readable storage mediumof claim 43, wherein the stored processor executable instructions areconfigured to cause the processor of the first mobile communicationdevice to perform operations such that the second motion corresponds tothe user moving the first mobile communication device away from his orher ear.
 45. The non-transitory computer-readable storage medium ofclaim 43, wherein the stored processor executable instructions areconfigured to cause the processor of the first mobile communicationdevice to perform operations further comprising: sending the message tothe at least one second mobile device indicating a transition from theprivate mode to the public mode.
 46. The non-transitorycomputer-readable storage medium of claim 45, wherein the storedprocessor executable instructions are configured to cause the processorof the first mobile communication device to perform operations furthercomprising: receiving a message from the at least one second mobiledevice indicating that the second mobile device has transitioned topublic mode.
 47. The non-transitory computer-readable storage medium ofclaim 46, wherein the stored processor executable instructions areconfigured to cause the processor of the first mobile communicationdevice to perform operations further comprising: providing a feedbackcue to the user of the first mobile communication device indicating thatthe second mobile device has transitioned to public mode.
 48. Thenon-transitory computer-readable storage medium of claim 43, wherein thestored processor executable instructions are configured to cause theprocessor of the first mobile communication device to perform operationsfurther comprising: suppressing communication at the first mobilecommunication device until an indication of user compliance with thetransition to public mode is detected.
 49. A non-transitorycomputer-readable storage medium having stored thereon processorexecutable instructions configured to cause a processor of a firstmobile communication device to perform operations comprising:communicating with at least one second mobile device using a firstcommunication infrastructure; detecting a first motion of the firstmobile communication device corresponding to a user moving the firstmobile communication device from a first position to a second position;transitioning to a second communication infrastructure in response tothe detected first motion, wherein transitioning to the secondcommunication infrastructure comprises reallocating resources used fortransmission, reception or display of visual media content tohigher-quality audio communication; and communicating with the at leastone second mobile device using the second communication infrastructure,wherein the detected first motion corresponds to the user moving thefirst mobile communication device to a position proximate the user'sear.
 50. The non-transitory computer-readable storage medium of claim49, wherein the stored processor executable instructions are configuredto cause the processor of the first mobile communication device toperform operations such that transitioning to the second communicationinfrastructure comprises using a noise cancellation feature.
 51. Thenon-transitory computer-readable storage medium of claim 49, wherein thestored processor executable instructions are configured to cause theprocessor of the first mobile communication device to perform operationssuch that transitioning to the second communication infrastructurecomprises switching between a 3G and a 4G network infrastructure. 52.The non-transitory computer-readable storage medium of claim 49, whereinthe stored processor executable instructions are configured to cause theprocessor of the first mobile communication device to perform operationsfurther comprising: detecting a second motion of the first mobilecommunication device corresponding to the user moving the first mobilecommunication device from the second position to the first position;transitioning to the first communication infrastructure based on thedetected second motion; and communicating with the at least one secondmobile device using the first communication infrastructure.